Štornik Aleksandra, Skok Barbara, Trček Janja
Department of Biology, Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, SI-2000 Maribor, Slovenia.
Department of Biology, Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, SI-2000 Maribor, Slovenia; Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova ulica 17, SI-2000 Maribor, Slovenia.
Food Technol Biotechnol. 2016 Mar;54(1):113-119. doi: 10.17113/ftb.54.01.16.4082.
Organic apple cider vinegar is produced from apples that go through very restricted treatment in orchard. During the first stage of the process, the sugars from apples are fermented by yeasts to cider. The produced ethanol is used as a substrate by acetic acid bacteria in a second separated bioprocess. In both, the organic and conventional apple cider vinegars the ethanol oxidation to acetic acid is initiated by native microbiota that survived alcohol fermentation. We compared the cultivable acetic acid bacterial microbiota in the production of organic and conventional apple cider vinegars from a smoothly running oxidation cycle of a submerged industrial process. In this way we isolated and characterized 96 bacteria from organic and 72 bacteria from conventional apple cider vinegar. Using the restriction analysis of the PCR-amplified 16S-23S rRNA gene ITS regions, we identified four different III and five different II restriction profiles for bacterial isolates from organic apple cider vinegar. Each type of restriction profile was further analyzed by sequence analysis of the 16S-23S rRNA gene ITS regions, resulting in identification of the following species: (71.90%), (12.50%), (9.35%) and (6.25%). Using the same analytical approach in conventional apple cider vinegar, we identified only two different III and two different II restriction profiles of the 16S‒23S rRNA gene ITS regions, which belong to the species (66.70%) and (33.30%). Yeasts that are able to resist 30 g/L of acetic acid were isolated from the acetic acid production phase and further identified by sequence analysis of the ITS1-5.8S rDNA‒ITS2 region as , and . This study has shown for the first time that the bacterial microbiota for the industrial production of organic apple cider vinegar is clearly more heterogeneous than the bacterial microbiota for the industrial production of conventional apple cider vinegar. Further chemical analysis should reveal if a difference in microbiota composition influences the quality of different types of apple cider vinegar.
有机苹果醋由果园中经过严格处理的苹果制成。在该过程的第一阶段，苹果中的糖分被酵母发酵成果汁。在第二个单独的生物过程中，产生的乙醇被用作醋酸菌的底物。在有机和传统苹果醋中，乙醇氧化成醋酸都是由酒精发酵后存活下来的天然微生物群引发的。我们从一个平稳运行的工业深层发酵氧化循环中，比较了有机和传统苹果醋生产过程中可培养的醋酸菌微生物群。通过这种方式，我们从有机苹果醋中分离并鉴定了96株细菌，从传统苹果醋中分离并鉴定了72株细菌。利用PCR扩增的16S-23S rRNA基因ITS区域的限制性分析，我们为有机苹果醋中的细菌分离株鉴定了四种不同的III型和五种不同的II型限制性图谱。通过对16S-23S rRNA基因ITS区域进行序列分析，对每种类型的限制性图谱进行了进一步分析，结果鉴定出以下物种：（71.90%）、（12.50%）、（9.35%）和（6.25%）。在传统苹果醋中使用相同的分析方法，我们仅鉴定出16S-23S rRNA基因ITS区域的两种不同的III型和两种不同的II型限制性图谱，它们属于（66.70%）和（33.30%）这两个物种。从醋酸生产阶段分离出了能够耐受30 g/L醋酸的酵母，并通过ITS1-5.8S rDNA-ITS2区域的序列分析进一步鉴定为、和。这项研究首次表明，用于工业生产有机苹果醋的细菌微生物群明显比用于工业生产传统苹果醋的细菌微生物群更加多样化。进一步的化学分析应该能够揭示微生物群组成的差异是否会影响不同类型苹果醋的质量。
